O-nitrobenzyl Caged Molecule Enables Photo-controlled Release of Thiabendazole.

Pesticides are essential in agricultural development. Controlled-release pesticides have attracted great attentions. Base on a principle of spatiotemporal selectivity, we extended the photoremovable protective group (PRPG) into agrochemical agents to achieve controllable release of active ingredients. Herein, we obtained NP-TBZ by covalently linking o-nitrobenzyl (NP) with thiabendazole (TBZ). Compound NP-TBZ can be controlled to release TBZ in dependent to light. The irradiated and unirradiated NP-TBZ showed significant differences on fungicidal activities both in vitro and in vivo. In addition, the irradiated NP-TBZ displayed similar antifungal activities to the directly-used TBZ, indicating a factual applicability in controllable release of TBZ. Furthermore, we explored the action mode and microcosmic variations by SEM analysis, and demonstrated that the irradiated NP-TBZ retained a same action mode with TBZ against mycelia growth.

Reversible Regulation of Succinate Dehydrogenase by Tools of Photopharmacology.

Succinate dehydrogenase (SDH) is extremely important in metabolic function and biological processes. Modulation of SDH has been reported to be a promising therapeutic target to SDH mutations. Current measures for the regulation of SDH are scarce, and precise and reversible modulation of SDH still remains challenging. Herein, a powerful tool for reversible optical control of SDH was proposed and evaluated utilizing the technology of photopharmacology. We reported photochromic ligands (PCLs), azobenzene-pyrazole amides (APAs), that exert light-dependent inhibition effects on SDH. Physicochemical property tests and biological assays were conducted to demonstrate the feasibility of modulating SDH. In this paper, common agricultural pathogens were used to develop a procedure by which our PCLs could reversibly and precisely control SDH utilizing green light. This research would help us to understand the target-ligand interactions and provide new insights into modulation of SDH.

Azobenzene-Avermectin B1a Derivatives for Optical Modulation of Insect Behaviors.

Naturally occurring avermectins are allosteric modulators of glutamate-gated chloride channels (GluCls) and possess exceptionally potent anthelmintic, acaricidal, and insecticidal activities. Here, we develop photoswitchable azobenzene-avermectin (ABAVM) derivatives, which can be photoactivated upon ultraviolet irradiation. After illumination, the best compound p-AB4″AVM had a 1.88-fold and 2.74-fold insecticidal activity enhancement toward Culex pipiens pallens and Mythimna separata larvae, respectively. p-AB4″AVM allows for optical regulation of dorsal unpaired median neuron membrane potential with a 2.15-fold fluorescence intensity decrease after illumination. p-AB4″AVM and p-AB5AVM enable optical modulation of the behavioral response of Culex pipiens pallens larvae with 1- and 4-fold reduced mobility upon irradiation, respectively. The ABAVMs could be used to reversibly manipulate GluCls with light and may be useful for the mechanistic study of macrocyclic lactone insecticides.